Response of bird community to gradual landscape transformation in Darmaga campus, IPB University, Bogor, Indonesia

When a landscape gradually transforms, the bird community that inhabits the landscape will also adapt and change accordingly. Long-term data on the bird-habitat relationship, however, is still lacking in the sub-urban tropical areas. The objective of this paper was to analyze the response of bird community along with the gradual transformation of the landscape. Darmaga Campus of IPB University (± 2.67 km2) was selected as the study area due to its landscape transformation for campus development/construction, and the availability of bird monitoring data. Data on landscape transformation were gathered from the IPB building construction book published in 2017, and bird community (1982-2020) were gathered from published reports and papers. During the observed period, Darmaga Campus that initially consisted mostly of old rubber plantation has been gradually transformed into various academic-related uses, such as some areas for buildings dan field laboratories. From 1982 to 2020, the cumulative bird species in the study area at least was 124 species. During the observed years, the bird community was highly dynamics (bird species number in 1982 = 41 species, 1985 = 39 species, 1986 = 68 species, 1991 = 68 species, 2001 = 39 species, 2003 = 72 species, 2013 = 52 species, 2020 = 99 species). New incoming species were Chestnut-winged Cuckoo, Asian Brown Flycatcher, Tiger Shrike, and babblers (e.g., Black-capped Babbler); Brown Shrike, White-rumped Shama, Oriental Magpie-Robin and Green Junglefowl have not been observed or have become increasingly rare in the last ten years. Meanwhile, Red-breasted Parakeet, Fulvous-breasted Woodpecker, Sunda Pygmy Woodpecker, Black Drongo, and Sooty-headed Bulbul are always present species. Bird species such as Orange-headed Thrush, White-rumped Shama, White-browed Shortwing, and Velvet-fronted Nuthatch are species that entered to rarely found species. Gradual landscape transformation, from an old rubber plantation into a mosaic of small patches of human-made ornamental plants, shrub, and tree plantation, turns out to be beneficial for some bird species, but could also disadvantageous for others, causing a dynamic bird community composition.


Introduction
The human population has continued to increase from time to time, and this increase has also been followed by an increase in land requirements [1]. The use of land by humans is carried out to fulfil all interests to maintain life, such as to produce food, use it for shelter, and various other purposes. The increasing human need for land has transformed the shape of a landscape a lot.
Transformations in a landscape have occurred in many areas, e.g., in the Darmaga Campus, IPB University, Bogor. In the past, the Darmaga Campus was founded in 1963, most of its area was an old rubber plantation, and there were only a few buildings. Then to fulfil academic needs, the campus area has gradually continued to develop until now. The Dramaga Campus landscape has undergone many transformations gradually due to area development by humans.
The development of an area can influence the existence of animals, especially birds. Birds are one of the animals that are very sensitive to changes in their environment. If the landscape undergoes transformations or disturbances that affect the bird habitat condition, the bird species composition in the landscape will also change [2,3], hence birds can be used as a bio-indicator to see changes in conditions environment [4] because the bird diversity in a place is closely related to their habitat conditions. Birds can respond in different ways to the landscape transformations that occurred. There are bird species that can adapt and survive from transformations in their habitat, but there are also bird species that are lost or become extinct due to habitat transformations. This causes the bird community to be dynamic due to transformations in the landscape. This paper aims to determine how birds respond to gradual landscape transformation at the Darmaga Campus.

Methods
This paper tries to analyze the shapes of landscape transformation on the Darmaga Campus in several periods and tries to relate to the bird species present in the area whose data is obtained from several research. Darmaga Campus of IPB University (± 2.67 km2) was selected as the study area due to its landscape transformation for campus development/construction, and the availability of bird monitoring data. Landscape transformation data were obtained from the IPB building construction book written by [5] in 2017, then the bird data in this paper were taken from the research results of [6][7][8][9][10][11][12][13]. The data on the bird species presence obtained from several previous research were then grouped into several groups based on presence criteria (Table 1) to find out which bird species can survive from changes in habitat, rarely found on Darmaga Campus, newcomer, and that cannot be found anymore in the last ten years. Cannot be found anymore in the last 10 years

Landscape transformation in Darmaga Campus, IPB University
The Darmaga Campus landscape has undergone many transformations since it was used as a campus until now. In 1963, when it was built as a campus, the Darmaga Campus area was an old rubber plantation from the Dutch colonial era. During the period 1963 -2017, many building constructions were carried out for academic, laboratory and residential purposes. Previously, at the beginning of the campus, almost the entire of Darmaga Campus area was the green area, namely forest or garden with very few buildings. As time goes by, to fulfil all academic needs, more and more developments are being made at the Darmaga Campus and further reducing the green area. The number of people is increasing and academic needs are increasing, the more building construction is being carried out. The following is a list of building construction carried out at Darmaga Campus, IPB University from 1963 -2017 (Table 2).  Table 2 The buildings built from 1963 -2017 in Darmaga Campus, IPB University [5] Period

Bird communities in Darmaga Campus, IPB University based on several previous research
There are at least 124 bird species founded in the study location based on several previous research results, which is relatively high for a tropical urban periphery. The number of bird species from several previous research results at Darmaga Campus can be seen in Figure 1. All of the species founded, then are grouped into several groups based on presence criteria (Table 3). Prescribed presence criteria are always present, intermittently present, rarely found, newcomer, and extirpated. There are 26 species included in the always present, 58 species intermittently present, 39 species rarely found, 103 newcomer and 23 extirpated species.   Table 3 Bird species presence from several previous research [6][7][8][9][10][11][12][13] which has been grouped based on several presence criteria (bird name and sequence based on [14] Common Name

Discussion
The Dramaga Campus landscape has changed gradually and can affect the bird communities in the landscape. In the past, the Darmaga Campus landscape was initially built by a campus as an old rubber plantation. Gradually, the Darmaga Campus has undergone a lot of development until now to fulfill academic needs. Transformations in a landscape can impact the animals in it, especially birds, because they are sensitive to changes in their habitat.
Regional development gradually will make the shape of landscape mosaic and heterogeneous. The development of the area can create threats in the form of fragmentation and habitat loss for animals, which forces them to determine whether they will emigrate to the new places, more suitable habitats, or survive and adapt to new conditions [15,16]. Birds will respond differently to any development in their habitat. There are bird species that can survive changes in their habitat, and others choose to avoid or disappear.  [17]. Besides, the Javan Munia species are seed-eating, usually founded in rice fields, and the Javan Kingfisher species are always founded in the Darmaga Campus landscape because this landscape can provide habitat for them in the form of rice fields and wet areas.
Meanwhile, in the rarely found group, species encountered such as Orange-headed Thrush, White-rumped Shama, White-browed Shortwing, and Velvet-fronted Nuthatch are shy bird species to human presence and require forested habitats [17]. Therefore, the increasing number of developments and the more human activities will have an impact on this type of bird.
In the newcomer group or new species that enter, there are bird species such as the Chestnut-winged Cuckoo, Asian Brown Flycatcher, Tiger Shrike, and babblers (e.g., Blackcapped Babbler). Meanwhile, species such as the Brown Shrike, White-rumped Shama, Oriental Magpie-Robin, and Green Junglefowl have not been observed or have become increasingly rare in the last ten years. The existence of bird species in a place is closely related to the conditions of the place to support birdlife. According to [18] that there are several factors determine the presence of birds in a place, namely the availability of food, a place to rest, play, breed, nest, perch, and take shelter. If bird habitat is disturbed, newcomer species may disappear or no longer be found, such as extirpated species.
The existence of area development carried out at the Darmaga Campus should be balanced with the fulfilment of bird habitat components to support birdlife. Some activities that can be carried out are protecting forested habitats for birds, intensifying the planting of bird feed sources, and planting trees.

Conclusion
The conclusion of this paper is the gradual landscape transformation that occurred at Darmaga Campus, IPB University, from previously forest and old rubber plantations to many building constructions, turns out to be beneficial for some bird species, but can also be detrimental for others, causing a dynamic bird community composition. There are several recommendations for area development activities so that the development can also consider the birdlife needs, such as protecting forested habitats for birds, intensifying the planting of bird feed sources, and planting trees.